Abstract

Background

This study investigates the relationships between health and lifestyle factors, age
and private health insurance (PHI) in a large Australian population-based cohort study
of people aged 45 years and over; the 45 and Up Study. Unlike previous Australian
analyses of relationships between health, lifestyle and PHI, it incorporates adjustment
for multiple confounding socioeconomic and demographic factors. Recruitment into the
45 and Up Study began in February 2006 and these analyses relate to the first 103,042
participants who joined the study prior to July 2008.

Results

The proportion with PHI decreased with increasing age. The factors independently and
most strongly associated with having PHI were: higher income; higher educational attainment;
not holding a health care concession card; not being of Aboriginal/Torres Strait Islander
origin; being a non-smoker; high levels of self-rated health and functional capacity;
and low levels of psychological distress. These factors increased the probability
of having PHI by 16% to 125%, compared to individuals without these characteristics.
PHI coverage was significantly but only marginally higher in people reporting non-melanoma
skin cancer (adjusted RR 1.04, 95%CI 1.03–1.05), prostate cancer (1.09, 1.06–1.11)
or an enlarged prostate (1.07, 1.06–1.09), those reporting a family history of a range
of conditions (e.g. 1.02, 1.01–1.03 for a family history of heart disease; 1.03, 1.02–1.04
for a family history of prostate cancer) and lower in people reporting diabetes (0.92,
0.91–0.94) or stroke (0.91, 0.88–0.94), compared to people who did not have these
medical or family histories. PHI was higher in those reporting certain surgical procedures
with RRs (95%CI) of 1.12 (1.09–1.15) for hip replacement, 1.10 (1.08–1.13) for knee
replacement and 1.12 (1.09–1.15) for prostatectomy, compared to those not reporting
these interventions.

Conclusion

Compared to the rest of the study population, those with PHI are richer, better educated,
more health conscious, in better health and more likely to use certain discretionary
health services. Hence, PHI use is generally highest among those with the least need
for health care. Whether or not people have PHI is more strongly associated with demographic
and lifestyle factors than with health status.